not-os

kernel

$ nix-build -A kernel
/nix/store/fq3pnbvjg28n2ywwibq9a48vi5hcnbil-linux-5.4.84

The kernel derivation results in an actual kernel, a bzImage file, but also in a set of kernel modules.

The modules are packaged in the shrunk derivation, which itself is used to create the initrd.